Distress Identification Manual for The Long-Term Pavement Performance Program (Fifth Revised Edition)

GLOSSARY

Adhesive Failure: Loss of bond (e.g., between the joint sealant and the joint reservoir or between the aggregate and the binder).

Aggregate Interlock: Interaction of aggregate particles across cracks and joints to transfer a load.

Approach Slab: Section of pavement just prior to joint, crack, or other significant roadway feature relative to the direction of traffic (also see "Leave Slab").

Binder: Brown or black adhesive material used to hold stones together for paving.

Bituminous: Like or from asphalt.

Bleeding: Identified by a film of bituminous material on the pavement surface that creates a shiny, glass-like reflective surface that may be tacky to the touch in warm weather.

Block Cracking: The occurrence of cracks that divide the asphalt surface into approximately rectangular pieces, typically 0.1 m² or more in size.

Blowup: The result of localized upward movement or shattering of a slab along a transverse joint or crack.

Centerline: The painted line separating traffic lanes.

Chipping: Breaking or cutting off small pieces from the surface.

Cohesive Failure: The loss of a material’s ability to bond to itself. Results in the material splitting or tearing apart from itself (i.e., joint sealant splitting).

Construction Joint: The point at which work is concluded and reinitiated when building a pavement.

Corner Break: A portion of a JCP separated from the slab by a diagonal crack intersecting the transverse and longitudinal joint, which extends down through the slab, allowing the corner to move independently from the rest of the slab.

Durability Cracking: The breakup of concrete due to freeze-thaw expansive pressures within certain aggregates. Also called "D" cracking.

Edge Cracking: Fracture and materials loss in pavements without paved shoulders which occurs along the pavement perimeter. Caused by soil movement beneath the pavement.

Extrusion: To be forced out (i.e., joint sealant from joint).

Fatigue Cracking: A series of small, jagged, interconnecting cracks caused by failure of the AC surface under repeated traffic loading (also called "alligator cracking").

Fault: Difference in elevation between opposing sides of a joint or crack.

Free Edge: Pavement border that is able to move freely.

Hairline Crack: A fracture that is very narrow in width, less than 3 mm.

Joint Seal Damage: Any distress associated with the joint sealant, or lack of joint sealant.

Lane Line: Boundary between travel lanes, usually a painted stripe.

Lane-to-Shoulder Dropoff: The difference in elevation between the traffic lane and shoulder.

Lane-to-Shoulder Separation: Widening of the joint between the traffic lane and the shoulder.

Leave Slab: Section of pavement just past a joint, crack, or other significant roadway feature relative to the direction of traffic.

Longitudinal: Parallel to the centerline of the pavement.

Map Cracking: A series of interconnected hairline cracks in PCC pavements that extend only into the upper surface of the concrete. Includes cracking typically associated with alkali-silica reactivity.

Patch: An area where the pavement has been removed and replaced with a new material.

Patch Deterioration: Distress occurring within a previously repaired area.

Polished Aggregate: Surface mortar and texturing worn away to expose coarse aggregate in the concrete.

Popouts: Small pieces of pavement broken loose from the surface.

Pothole: A bowl-shaped depression in the pavement surface.

Pumping: The ejection of water and fine materials through cracks in the pavement under moving loads.

Punchout: A localized area of CRCP bounded by two transverse cracks and a longitudinal crack. Aggregate interlock decreases over time and eventually is lost, leading to steel rupture and allowing the pieces to be punched down into the subbase and subgrade.

Raveling: The wearing away of the pavement surface caused by the dislodging of aggregate particles.

Reflection Cracking: The fracture of AC above joints in the underlying JPC layer(s).

Rutting: Longitudinal surface depressions in the wheel paths.

Scaling: The deterioration of the upper 3 to 12 mm of the concrete surface, resulting in the loss of surface mortar.

Shoving: Permanent longitudinal displacement of a localized area of the pavement surface caused by traffic pushing against the pavement.

Spalling: Cracking, breaking, chipping, or fraying of the concrete slab surface within 0.6 m of a joint or crack.

Transverse: Perpendicular to the pavement centerline.

Water Bleeding: Seepage of water from joints or cracks.

Weathering: The wearing away of the pavement surface caused by the loss of asphalt binder.